Does Intelligence Affect Mental Health? A HealthCentral Explainer

This is an interesting question; there have been highly publicized studies linking creativity in famous, intelligent people to mental illness - think Ernest Hemingway, Tennessee Williams, Virginia Wolf, and Mozart. And while creativity has been linked to depression, bipolar disorder, and schizophrenia, little research had been done on whether there was a direct link between intelligence and mental health. But new research, published in Psychological Medicine, in fact, suggests that there is a link between lower IQs and lower levels of happiness.

How was the research conducted?

Researchers from University College of London measured categorical and continuous IQs, and compared them to measurements of perceived happiness. IQ assessment was performed according to the National Adult Reading test, and perceived happiness was measured by a questionnaire. For example, one question on the questionnaire read: “Taking all things together, how would you say you were these days – very happy, fairly happy, or not too happy?” All participants lived in England, were at least 16 years old, and lived in a private household.

Those with a lower IQ were more likely to be unhappy compared to their brighter peers. Results revealed that 43 percent of the participants had an IQ between 120 and 129 and reported being “very happy.” In contrast, the 12 percent of participants with an IQ between 70 and 79 reported the lowest level of happiness.

Why are they linked?

According to Dr. Angela Hassiotis, other factors associated with a lower IQ are likely influencers. People with a lower IQ were less likely to report high happiness levels, in part due to inherent socio-economic disadvantages such as poverty and education opportunities. This coincides with an earlier study which found that happiness rises as income reaches $75,000 a year, but doesn’t increase measurably above that level and decreases the more it falls below that level. Those living in poverty also are more likely to be unhappy because they need more assistance with daily living, tend to have poorer health and report more symptoms of psychological distress.

Another recent study found a distinction between mental health conditions linked to poverty and those suffering from a psychiatric disorder, a distinction often now ignored by mental health care providers.

Rutgers researchers found that poverty – particularly in poor mothers--was the likely cause of their generalized anxiety disorder (GAD). Physical need and financial instability caused their mental distress, not an “internal malfunction.”

Additionally, last week the Gallup-Healthways Well-Being Index revealed that people living in poverty are twice as likely to be depressed or affected by a variety of other chronic health problems, including asthma, diabetes, and obesity. This is likely because those in poverty reported having more difficulty getting access to health insurance, affording medicine, finding a physician, or even being able to get medications near their homes.

Finding solutions

If poverty is the root of the mental health problem, the treatment is quite different from that of a physical psychiatric disorder. According to associate professor Judith Baer, of the School of Social Work at Rutgers, “While supportive therapy and parent skills-training are often helpful, sometimes the most appropriate intervention is financial aid and concrete services.” Ultimately the study revealed that anxiety, particularly in young mothers, is usually not a psychiatric disorder, but a reaction to environmental stresses. So labeling someone with an inaccurate diagnosis all too often leads to ineffective treatment, in addition to social stigma.

The findings linking lower IQ to unhappiness reveal some evidence that early intervention for young children living in socially deprived circumstances could have a positive impact on their well-being and prospects. As study co-author Dr. Afia Ali suggested, “Such interventions are likely to be costly, but the initial costs may be offset by future benefits such as a reduced reliance on state benefits and better mental and physical health.”